It is something so fundamental, yet it failed a Texas family.
"Dog gone it, somebody should've answered," said Hank Hunt, sitting in a Dallas hotel room, reliving the heartbreak that happened 150 miles east.
His daughter, Kari Hunt Dunn, was murdered in a Marshall, Texas hotel bathroom last December. Police said her estranged husband was the killer.
Dunn's three children were in the hotel room and heard the commotion. Her oldest daughter did what she was taught to do: She dialed 911.
"She tried four times, and it didn't work," said DaLonna Hunt, the dead woman's mother.
It didn't work because the child didn't first dial a "9" to get an outside line before dialing 911.
"She said she got what sounded like static," DaLonna Hunt said. "She ultimately got help from outside the room, but you're talking minutes, not seconds. Would those seconds have saved our daughter? We know the minutes didn't."
The Hunts started an online petition to force hotels to upgrade phone systems, believing no one in a hotel or even large office complex should have to dial "9" before 911.
"I wanted to get at least 100 signatures to take to my congressman and demand there be a law," Hank Hunt said.
His online petition is approaching half a million signatures now. "Never dreamed it would take off like this," he admits.
One reason it's gained so much steam is that people in high places have signed it, including Mark Fletcher, who works for Avaya, one of the nation's largest communications companies.
"It's something that can be fixed for free, and that's the sad part," he said. Fletcher handles the company's public safety solutions. He was aware of the 911 problem from hotel rooms, and was pushing for changes long before tragedy struck the Hunt family.
When he heard Kari Dunn's story, he wrote a letter to the FCC. Within days, commissioners were listening to him.
The FCC started pressing hotels for answers, and the hotel industry formed a task force to look at the issue.
The FCC didn't like what it found.
An industry survey showed a direct dial to 911 worked in less than 45 percent of properties owned by a franchise, and just 32 percent of properties owned by independent operators.
Some properties are now voluntarily upgrading, but the Hunts hope petition signatures keep coming in favor of "Kari's Law," which would require compliance.
"It's a shame we have to pass a law to get hotels to wake up, but, you know, that's change," Fletcher said. "Little by little. One by one."
The FCC is leaning on telephone service providers, asking them to step up and update systems, too.
Fletcher said changing systems not just in hotels but also in office buildings would not be that difficult.
"In telephone systems long ago, you'd dial a '9' for an outside line," he explained. "But the phone system doesn't need the '9' to know it's an outside call now. Basically it connects the digits and knows I'm calling New Jersey, so it send the call that way."
"If it was a technical problem that'd be one thing, but it's not. It's just an awareness problem," he said.
Fletcher has created a slogan for the Hunts' campaign: "No 9 Needed."
The Hunts came to Dallas on Fletcher's invitation. They attended an Avaya conference. Hank Hunt asked questions and people got to meet this determined father face-to-face.
"People ask me if I'm doing it for closure," Hunt said. "No. There never will be. I'm doing this to prevent another nine-year-old from having to go through what my granddaughter did."
He's proud he's seeing chage. But pride doesn't take away pain.